Activated factor Xa, whose major practical role is the generation of thrombin by the limited proteolysis of prothrombin, holds a central position that links the intrinsic and extrinsic activation mechanisms in the final common pathway of blood coagulation. The generation of thrombin, the final serine protease in the pathway to generate a fibrin clot, from its precursor is amplified by formation of prothrombinase complex (factor Xa, factor V, Ca2+ and phospholipid). Since it is calculated that one molecule of factor Xa can generate 138 molecules of thrombin (Elodi, S., Varadi, K.: Optimization of conditions for the catalytic effect of the factor IXa-factor VIII Complex: Probable role of the complex in the amplification of blood coagulation. Thromb. Res. 1979, 15, 617-629), inhibition of factor Xa may be more efficient than inactivation of thrombin in interrupting the blood coagulation system.
U.S. Patent Application Publication No. 2003/0191115, which is herein incorporated by reference, discloses 3-(1-hydroxy-1-methyl-ethyl)-1-(4-methoxy-phenyl)-6-[4-(2-oxo-2H-pyridin-1-yl)-phenyl]-1,4,5,6-tetrahydro-pyrazolo[3,4-c]pyridin-7-one (hereinafter referred to as “Compound (I)”):
Compound (I) is a highly potent and selective inhibitor of coagulation Factor Xa and thus is useful in preventing or treating thromboembolic disorders.
Treatment or prevention of the foregoing disorders may be accomplished by administering a therapeutically effective amount of Compound (I) to a human or animal subject in need of such treatment or prevention. The treatment with Compound (I) may be accomplished by its use as a single compound, as a pharmaceutical composition ingredient, or in combination with other therapeutic agents. Compound (I) may be administered by oral administration, continuous intravenous infusion, bolus intravenous administration or any other suitable route such that it preferably achieves the desired effect of preventing the Factor Xa induced formation of thrombin from prothrombin.
Crystalline forms of Compound (I) have not been known to exist previously. There exists a need for crystalline forms which may exhibit desirable and beneficial chemical and physical properties. There also exists a need for reliable and reproducible methods for the manufacture, purification, and formulation of Compound (I) to permit its feasible commercialization. The present invention is directed to these, as well as other important aspects.